Question

x − 7y = 20
x + 12y = −1
find the value for y

Answer 1

Hi marmar, so do you know the substitution method?

Answer 2

Basically we're looking to build an equation that only has one variable

Answer 3

\[x - 7y = 20\]
becomes:
\[x = 20 + 7y\]

Answer 4

So can you write your second equation using this value for x?

Answer 5

That is one way you could multiply your first equation by -1 and then add the equations.

Answer 6

Good point myin - that's probably easier here huh?

Answer 7

Maybe they like your better.

Answer 8

I ALWAYS think in terms of substitution - to a fault ;)

Answer 9

wow two moderators on one problem!

Answer 10

Do you prefer substitution or elimination @ marmar?
(

Answer 11

Ha satellite - two moderators, a resident expert, and no question asker...